The present invention relates to the formation of multi-layer stacks of sheets and, more particularly, to the formation of stacks of adhesive-backed sheets of paper to form note pads or the like.
Apparatus and methods for laying up stacks of sheets of paper to ultimately form note pads, writing pads, books, or the like are well known in the art. Oftentimes the sheets are bound together along one edge of the stack by an adhesive coating such that individual sheets may be torn from the pad. The lay up of stacks of sheets of paper prior to the application of an adhesive to bind one edge of the stack is a relatively simple and straightforward operation.
In recent years, the development of ultra-removable adhesives has led to the innovation of adhesive-backed notes or sheets in pad form which may be individually removed and subsequently repeatedly applied and removed from other surfaces. The low tack, ultra-removable adhesives are typically applied in a thin strip on one side adjacent the edge of each sheet in the stack. However, the presence of the adhesive coating interferes with uniform stacking of sheets using conventional sheet stacking methods and apparatus. This has required the development of alternate systems which must be substantially more complex to accommodate the adhesive layer on one side of the sheet which inhibits virtually any sliding movement between sheets as they are stacked.
It would be desirable to have a system which is capable of assembling stacks of multi-layer sheets which are coated on one side with a tacky adhesive in a manner which retains good sheet alignment and is capable of high volume production.